Braking attachment for vehicle motors



BRAKING ATTACHMENT FOR VEHICLE MOTORS Filed June 5, 1929 INVENTOR W11.lieu/i2? ATTORNEY 0.5.5 @uw' a I I 1 BY Patented June 30, 1931 UNITEDSTATES PATENT OFFICE 2 WILLIAM nAsToN HEWITT. or CUMBERLAND, MARYLAND,ASSIGNOR F 0NE-HALF To ORA M. DOOLITTLE, or CUMBERLAND, MARYLAND BRAKINGATTACHMENT roavnnrcnn MOTORS f Application filed June 5, 1929; SerialNo. 368,659.

1 This invention relates to vehicle motor attachments designed to causethe motor of a vehicle to function as a brake, particularly indescending grades and has the advantage of saving wear on the usualbraking mechanism, of uniformly applying braking force, and of coolingthe motor. An object of the invention is the provision of mechanismoperable from the dash by the vehicle operator for effecting closure ofthe exhaust valves of the motor without interference with the normalaction of their operating mechanism; and reversely, for reconditioningthe valves for normal operation of said mechanism.

Another object of the invention is the provision in conjunction withmechanism as above described, of means coincidently operable to breakthe fuel suction through'the 2o carburetter from the intake manifold andto supply motor cooling air in lieu of fuel,

and reversely to restore carburetter suction and cut off said coolingairsuction.

It is a further object of the invention to provide mechanism foreffecting the above described functions which may be'attached to andform part of the motor without interfering with its normal operation orrequiring special initial motor constructlon essential to itsinstallation. y

With the foregoing and other objects 1n view, the invention consists incertain novel 7 features of construction, and combinations andarrangements of parts, as will be more fully hereinafter set forth andpointed out in the claims. The nature of the invention will be morefully comprehended from the following detailed specification which is tobe read in 0 conjunction with the accompanying drawings forming partthereof, and in which Figure 1 is a fragmentary diagrammatic view of thedash and motor of a vehicle with the device of the present inventionapplied theret0.'

Figure 2 is a view in transversesection and on an enlarged scale showinga push rod, rocker arm, rocker .arm shaft and exhaust tie valve with the"eccentric onthe rocker .arm

shaft in inoperative position permitting normal operation of the motor.

Figure 3 is asimilar view with the normally stationary rock arm shaftpartially rotated to shift the rocker arm into inoperative re lation toits push rod and away from the exhaust valve to permit the latter toremain closed.

Figure 4 is a fragmentary perspective view of the dash operatedmechanism and its operating' connections to the air valve and rocker armshaft.

The device of the present invention is designed for use in connectionwith vehicle motors of the overhead valve type employing rocker armsmounted ona stationary shaft and rocked through push rodsfrom the valve.cam shaft to depress and open the intake and exhaust valves against thetension of coiled springs normally effective to close said valves. p InFigure 1 of the drawings showing diagrammatically the dash and motor ofa vehide, the instrument board is indicated at l and the motor block at2; The carburetter 3 is connected through the usual intake mani fold 4with the intake valve ports in the block. The exhaust manifold is shownat 5' and the cover for the-rocker arms and shaft and the upper ends ofthe push rods and valves is shown coventionally at 6. v V

The construction and the mounting of the rocker arms, push rods andvalves in the motor block arestanda'rd and need not be detailed in full.In Figures 2 and 3, I show a single push rod, rocker arm and exhaustvalve, with the rock arm shaft modified in accordance with the presentinvention;

Thepush rod 7 mounts on its upper end a sleeve 8 formed at its upper endas a cupped head 9. of semi-spherical outer contour. The

rocker arm 10 is formed intermediate of its ends with the enlargedsleeve portion 11 by means of'which it is journaled upon the stationaryrocker arm shaft 12 and at one end is formed with a vertical threadedstem 13 having a ball 14 at its lower end to seat in the cuppedsemi-spherical head 9 of the push rod 6. lock nut 15 holds the stem 13111 adjustedposition inthe end'of the rocker arm. The rocker arm shaftis usually hollow from adjacent its rear to its front end to provide anoil passage through which oil is forced to its outer end, transverse oilducts in the shaft and rocker arms carrying some of the oil to the stems13 and thence to their ball ends 14:.

Since in accordance with the present invention, provision is made forlifting the rocker arm to raise the ball 1i above and in inoperativerelation to the upper end of the push rod 9, I provide a cupped sleeve16 threaded upon the stem 13 and depending to enclose the ball 14, thesleeve 8 and its tappet head 9 therewithin to maintain them inal-ineme'n-t when the rocker arm with ball 14 and its stem are lifted asabove described.

The other end 17 of the rocker arm overlies the tappet 18 on the upperend of the stem 19 of the exhaust valve whose spring 20 normally tendsto move and hold the valve in closed position.

In accordance with the present invention, the rocker arm shaft, which isnormally stationary and is hollow to provide an oil duct, is providedwith eccentrics for effecting a bodily lifting movement of the rockerarms for the exhaust valves to inoperative position relatively to theirpush rods and valve tappets, and provision is made for effecting fromthe dash a rocking movement of the rocker arm shaft to effect thisresult through the eccentrics.

The rocker-arm shaft 12 in standard motors of the overhead valve type ismounted in spaced bearing supports secured to the top of the cylinderblock and extends through and serves as a bearing for the intermediatesleeved portion or hub 11 of the rocker arms. In accordance with myinvention, those portions of the shaft 12 which extend through the hubsleeves '11 of the exhaust valve rocker arms are provided witheccentrics, of which one, only, is shown in Figure 4, and the exhaustvalve rocker arms are provided with hub sleeves of corresponding andincreased diameter to fit the eccentrics. In the position of normaloperation of the motor with the exhaust valves, their push rods androcker arms functioning, the eccentrics 21 will extend downwardly asshown in Figure 2. A half turn of the shaft 12, which will affect therocker arms of the exhaust valves only, will effect a bodily liftingmovement of the exhaust valve rocker arms to a point where their pushrod engaging ballen ds liare lifted above the range of operation oftheir push rods and will correspondingly lift the opposite ends of therocker arms above the valve tappets 18 permitting the exhaust valves toremain closed. This last position of the exhaust valve rocker arms isshown in Figure 3.

The means which effects this turning movemen-t of the rocker arm shaftis also, in

accordance with my I invention functions to open an air line to theintake manifold 4: above the carburetter with the result that suctionthrough the carburetter by the motor is broken and air will be drawn ininstead. With the exhaust valves closed the air drawn in is alternatelycompressed and expanded as the pistons move up and down in theircylinders, and an effective braking action results, without wastage offuel.

To attain these results, I have provided the following mechanical aids.A rock shaft 22 extends through a bushing 23 in the instrument board 1and through a bore 2i in the dash 25 to terminate at its forward endadjacent the rear end of the motor block. The rear end of the shaftprojects through the instrument board and mounts an operating handle 26spaced from the instrument board by an appropriate sleeve as shown inFigure The forward end of the shaft carries a crank arm 27 (Figure 4)pivotally connected by a cross link 28 to a corresponding crank arm 29upstanding from the rear end of the rocker shaft 12 as shown in Figure 4and providing a rocking connection between said shafts.

A bracket 30 suitably secured to the rear end of the motor block mountson its upper end an air valve 31 having an air intake mouth 32. An airpipe 33 extends from the opposite end of the valve casing to and isplugged into the intake manifold 4. The usual valve plug bored to placethe intake 32 and pipe 33 into communication is seated in the valvecasing, the stem 34 of theplug having a. crank arm offset forwardlytherefrom and provided with a bifurcated front end 35 embracing a pin 36upstanding from the link 23 intermediate of its ends.

A half turn imparted to the rock shaft 22 through its operating handle16 on the instrument board will move the exhaust rocker arm eccentrics21 from the position shown in F igure 2 to that shown in Figure 3 withthe rocker arms lifted to and maintained in in operative relationrelatively to their push rods and exhaust valve ta-ppets. At the sametime, the longitudinal movement of the link 28 in transmitting rotarymotionfrom the rock shaft 22 to the rocker arm shaft 12, will, throughits pin 36 and the bifurcated crank arm 35, move the valve plug to openthe air intake to the intake manifold 4 of the motor, thereby'breakingsuction from the cylinders through the manifold to the carburettor andpreventing wastage of fuel as the compreslit] - tive.

at any time and in either position of adjustment.

With the exhaust valve rocker arms lifted as described to close theexhaust valves, the cycle of operations with the usual four cycleinternal combustion motor of a vehicle is as follows, the action withone cylinder and piston being typical. 7

On the first (and down) stroke of the piston, the intake valve opens andair is drawn into the cylinder. On the second (and up) stroke the intakevalve is closed, the exhaust valve is closed and the air is compressed.On the 3rd stroke (2nd downstroke) the piston is moved downwardly freelyby the gravity running of the vehicle with the compressed air expanding.On the 4th stroke (second upstroke), the exhaust valve being closed, theair is again compressed.

On the first (and down) stroke of the next cycle, the intake valve opensand the air pres-' sure in the cylinder is restored to atmospheric andthe cylinder cooled by the fresh air drawn in; on the second (and up)stroke, the air is compressed and so on as in the first cycle. Withthese cycles occurring in staggered sequence in the several cylinders ofthe usual multiple cylinder vehicle motor, it will be evident that asmooth and uniform braking action through compression is secured,without wastage of motor fuel and the danger of back-fire when the rockshaft is turned for normal motor operation and the ignition.

switched on.

The mechanism is essentially simple in its structural features andtherefore may be economically manufactured. It may be used with standardforms of overhead valve motors without requiring departure from theirdesign and construction.v While the structural features disclosedrepresent a preferable form of the device, they are intended asillustrative of the invention rather than restric- Hence, it will beunderstood that changes are contemplated in its structure adapting theconstruction to different conditions of manufacture and usein'consonance with the spirit of the invent-ion and the scope of theappended claims.

What I claim, therefore, and desire to secure by Letters Patent is 1. Aninternal combustion motor having intake and exhaust valves, valveoperating push rods, rocker arms connecting at their opposite ends withthe push rods and intake and exhaust valves, a rocker arm shaft uponwhich said rocker arms are journaled interarms of the intake valves andinoperatively to position the exhaust valve rocker arms relatively totheir push rods and valves, an air feed conduit communicating with theintake manifold of the motor and having a rotatable air inlet valvetherein, and an operating member having connections with said rocker armshaft and with said air valve effective in one direction of movement torotate said rocker shaft to said exhaust valve closing position andcoincidently to turn said air inlet valve to air intaking position, andreversely movable to turn said rocker shaft to normal valve operatingposition and coincidently to close said air inlet valve.

2. In a vehicle motor having normally closed intake and exhaust valves,individual rocker arms for moving individual valves to open position andmotor operated push rods separate therefrom, for periodically engagingand moving individual rocker arms in valve opening direction, a rockshaft upon which said rocker arms are individually j ournaledintermediate oftheir ends, having eccentric portions thereon upon whichthe exhaust valve rocker arms, only, are journaled and by rotatorymovement of which said exhaust rocker arms are moved to and frompositions placing their opposite ends in push rod contacting and exhaustvalve opening relation to other positions beyond the area of operatingcontact with said push rods and I mediate of their ends, said shafthaving those 7 portions journaling the rocker arms of the exhaust valvesformed as eccentrics effective in one position of the shaft to permitnormal push rod actuation of both intake and exhaust valve rocker armsand valves, and effective in a rotated position of the shaft to permitnormal push rod actuation of the rocker

